25 ml of solution of Fe2+ ions was titrated with a solution of the oxidizing agent Cr2O72- ,50 ml of 0.01 M K2Cr2O7 solution was required . what is the molarity of the Fe2+ solution ?
Answers
The equation to the above reaction is:-
Cr2O72- + 6Fe2+ + 14 H+ -> 2 Cr3+ + 6 Fe3+ + 7H20
Given, Concentration of K2Cr2O7 = 0.01 M
Volume of K2Cr2O7 = 50 ml
Therefore, moles of K2Cr2O7 present = ?
M = n/V
0.01M = (n/50)*1000
n = (0.01 * 50 )/1000
= 0.0005 moles
1 mole of K2Cr2O7 -> 6 moles of Fe2+
0.0005 moles of -> 6 * (0.0005)= 0.003 moles of Fe2+
Therefore, the strength of Fe2+ solution required is =?
V= 25ml = 0.025l
n= 0.003 moles
M=?
M= n / V (in litres)
= 0.003/ 0.025
= 0.12M
Ans:- 50ml of 0.01M K2Cr2O7 solution would require 25ml of 0.12M solution of Fe2+.